> ## Documentation Index
> Fetch the complete documentation index at: https://docs.rawchunks.space/llms.txt
> Use this file to discover all available pages before exploring further.

# Update a stem mixer

> Persist gain, pan, mute and solo for one stem.

These fields describe arrangement state. Your player or renderer applies the audio processing. This request does not bounce a new master.

## Headers and parameters

<ParamField path="stemId" type="string" required>
  Resource ID.
</ParamField>

<ParamField header="x-session-user-address" type="string" required>
  Selected account address. Required for owner-scoped reads and writes. It identifies the account; your product must authenticate its own users.
</ParamField>

## JSON body

<ParamField body="volume" type="number">
  Linear gain. 1 is unity. Minimum: `0`.
</ParamField>

<ParamField body="pan" type="number">
  Range: `-1` to `1`.
</ParamField>

<ParamField body="is_muted" type="boolean" />

<ParamField body="is_solo" type="boolean" />

## Response (200)

Success.

<ResponseField name="id" type="string" required />

<ResponseField name="song_id" type="string" required />

<ResponseField name="name" type="string" required />

<ResponseField name="url" type="string" required />

<ResponseField name="volume" type="number">
  Linear gain, 1 is unity. Minimum: `0`.
</ResponseField>

<ResponseField name="pan" type="number">
  Range: `-1` to `1`.
</ResponseField>

<ResponseField name="is_muted" type="boolean" />

<ResponseField name="is_solo" type="boolean" />

<ResponseField name="waveform_peaks_url" type="string | null" />

<ResponseField name="created_at" type="string" />

## Errors

Failed JSON responses contain an `error` string. Check the HTTP status before reading a successful result. See [job handling](/dev/guides/jobs) for interrupted or uncertain submissions.

| Status | Meaning |
| - | - |
| `400` | Invalid request. |
| `403` | Account does not match resource. |
| `404` | Resource not found. |
| `409` | Resource conflict; reload state or open an editable version. |
| `500` | Request failed. |

<RequestExample>
  ```bash cURL theme={null}
  curl --fail-with-body -X PATCH "$RAWCHUNKS_API/api/editing/mixer/$(jq -nr --arg v "$STEM_ID" '$v|@uri')" \
    -H "x-session-user-address: $USER_ADDRESS" \
    -H "Content-Type: application/json" \
    --data "$(jq -nc '{
    "volume": 0.8,
    "pan": -0.2,
    "is_muted": false,
    "is_solo": false
  }')"
  ```
</RequestExample>


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